Impact switch



K. W. JEWELL Nov. 15, 1966 IMPACT SWITCH Filed July 25, 1965 4 IO AUTOMOBILE r REAR DECK BREAKABLE ROD 29 IIIIII '26 WEIGHT INVENTOR KEITH W. JEWELL BY WQ ATTORNEYS United States Patent Ofifice 3,286,955 Patented Nov. 15, 1966 3,286,055 'IMPACT SWITCH Keith W. J ewell, 340 E. William St., Ann Arbor, Mich. Filed July 23, 1965, Ser. No. 474,340

4 Claims. (Cl. 20061.45)

The present invention relates generally to an impact switch and, more particularly to apparatus operable either upon impact, or at will, for providing a flashing warning light.

Over the past quarter-century, with the advent of high speed travel, there has been a very sharp increase in the number and severity of accidents which occur annually on our Nations roads. Many of these accidents are of the chain-collision type. Specifically, a typical chain accident may be caused when a single vehicle collides with an object, such as a tree, lamp pole, pedestrian, or other vehicle. Also typically, the vehicle and/ or other objects, immediately after the accident, may be located upon a roadway, and constitute obstructions to traffic. The presence of obstructions on the roadway after an accident is often the cause of additional and far more serious accidents, Furthermore, in many of these accidents, whether several vehicles or only one vehicle is involved, after the impact, the passengers are unconscious and incapable of signalling for assistance. The present invention is opera tive to overcome these serious motoring problems by providing a novel switch which automatically actuates a flashing warning light upon impact. The flashing warning light is then effective to signal for assistance in the event that the passengers are unable to do so and to warn oncoming traffic of the present of an obstruction upon the roadway.

It is, therefore, an object of the present invention to provide a flashing warning light which will help prevent accidents by signalling on-coming motorists of a road hazard ahead.

, It is a further object of the present invention to provide a flashing warning light which will automatically signal for help in the event that the participants in an accident are unconscious or otherwise disabled.

A still further object of the invention is the provision of a warning light which may be operated either manually or by an impact switch.

It is a further object ofv the invention to provide an impact switch which includes a frangible switch operating element which breaks when there is excessive acceleration or deceleration, as can occur upon impact.

Briefly describing the invention, it is contemplated that a light bulb within a globe will be mounted at any convenient location on an automobile, the light being adapted to be turned on either manually at will or automatically upon impact. The automatic actuating mechanism comprises an impact switch, a flasher, and a dry cell battery, all mounted in a suitable container in a convenient location, preferably adjacent the light bulb. The impact switch consists of a frangible rod, one end of which supports one contact of a terminal pair and the other end of which coacts with a metal weight, or other inertial element, in such a manner as to be capable of receiving a transverse force delivered by a shift in the position of the weight. This end of the frangible rod may, for example, be disposed within an aperture located within the metal weight or it may be imbedded therein. Intermediate the two ends of the rod is a fixed support. At the moment of impact, the weight is suddenly shifted and, since the fixed support is immovable, the rod breaks. This allows the movement of the contact end of the rod against the other contact of the terminal pair. The closing of these terminals closes a circuit between the dry cell, the flasher and the light bulb providing a flashing warning for other motorists. In order to actuate the flashing light manually a single-pole-single-throw switch it placed across the contacts of the terminal pair.

The impact switch of the present invention is ideally suited for the present purpose. It has a minimum number of parts and is, therefore, very reliable and not subject to failure. The Weight has complete freedom of motion in a horizontal plane and will break the frangible rod regardless of the direction in which the vehicle may be traveling at the moment of impact. There is only one actuating element, i.e. the weight, and there are no other elements which may become inoperative after extended periods of non-use, or by virtue of the impact. The impact switch of the present invention is not subject to false alarms since the frangible rod may be made resistant to all normal accelerations and decelerations short of an actual impact.

It is therefore an additional object of the present invention to provide a reliable, relatively inexpensive impact switch and warning system- The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of one specific embodiment thereof, especially when taken in conjunction with the accompanying drawing, wherein:

FIGURE 1 shows the warning system of the present invention; and

FIGURE 2 shows the details of the impact switch.

Referring now to the drawing, and, more particularly, to FIGURE 1 thereof, the details of the warning system are shown. A light 1 is mounted on a support 2 within a globe 3. The light may be mounted at any convenient location within a vehicle and preferably, in an automobile, is mounted on the rear deck 4, behind the back seat cushion, inside the car. The actuating mechanism for the. light is located within a suitable container 5 which may be located at any convenient location but preferably immediately below the light 1 under the rear deck. The container 5 includes a dry cell battery 6, a flasher 7, an impact switch 8, and a single-pole-single-throw switch 9. A first terminal of light 1 is connected to a first terminal of battery 6 by a conductive lead 10. The second terminal of battery 6 is connected to a first terminal of flasher 7 by conductive lead 11. The second terminals of light 1 and flasher 7 are connected to the two terminals of impact switch 8 by conductive leads 12 and 13, respectively. A series circuit is thereby formed in which actuation of impact switch 8 will cause current to flow from battery 6 through flasher 7, to light 1 and then back to battery 6 causing light 1 to flash on and off at a rate controlled by flasher 7.

In order to provide manual actuation of light 1, switch 9 is placed in parallel with switch 8 by connecting the two terminals of switch 9 to the two terminals of switch 8 via conducting leads 14 and 15. Actuation of switch 9 thereby causes current to flow from battery 6, through flasher 7, through switch 9, bypassing impact switch 8, to light 1 and back to battery 6. The switch 9 need not necessarily be mounted on the rear deck 4, as shown, but may be placed in any convenient location such as on the instrument panel at the forward end of the vehicle.

Referring now to FIGURE 2, the novel construction of the impact switch of the present invention is shown. Impact switch 8 includes a frangible rod 20 which is made of glass or any other readily breakable substance. Rod 20 passes through supporting collar 21 and supports, at one of its ends, one contact 22 of a terminal pair 23. Contact 22 is a thin strip or resilient metal which has one end fastened to the supporting collar 21, near the perimenter thereof. Immediately below the other end of contact 22, is located another contact 24 of terminal pair 23. The contacts 22 and 24 each may have any convenient shape, but preferably there is sufficient area of contact between them so that exact registration is not necessary. The contacts may be fastened to the collar 21 with any suitable fastening means, such as screws, rivets, etc. The other end of rod 20 is disposed within the aperture 26, located at the center of the weight 25. The weight 25 may be of any shape, but preferably is in the shape of an annulus, and is adapted to freely slide on the bottom of container 8 in any direction. Alternatively, the rod 20 may be imbedded in the metal weight if desired.

In operation, rod 20 is maintained in a vertical position by collar 21 and weight 25 and supports contact 22 so that there is no connection'between contact 22 and contact 24. Normally, rod 20 also maintains weight 25 centered in container 8 and is of sufficient strength to prevent movement of weight 25 under normal acceleration and deceleration. At the moment of impact, however, weight 25 is suddenly shifted enough'to break rod 20. The resilient contact 22, which has been retained in a deformed, or stressed, state by the rod 20, then springs downward making direct contact with the fixed contact 24. This closes the electrical circuit and actuates the signal.

While I have described my invention in its application to automobiles, it will be appreciated by one skilled in the art that it is not so limited and may be used wherever it is desired to have an impact actuate a warning signal, such as a born or the like.

Furthermore, while I have described a system which is completely self contained, it should be clear that the system can take advantage of components already found on an automobile. Specifically, the system could use the cars battery, flasher and parking lights.

While I have described and illustrated one specific embodiment of my invention, it will be clear that variation of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention as defined in the appended claims. 1

I claim:

1. An impact switch comprising:

an inertial element;

a frangible rod having a longitudinal axis and supported at one end thereof by said inertial element;

a first electrical contact supported by the other end of said frangible rod;

first means intermediate the ends of said frangible rod for preventing lateral movement of said rod but allowing longitudinal movement of said rod;

a second electrical contact; and 'second "means for supporting said second electrical contact intermediate said first electrical contact and said first means whereby breakage of said rod by movement of said inertial element causes longitudinal movement of said rod so that contact is made between said first and second electrical contacts.

2. The impact switch of claim 1 Wherein' said inertial element is a metal weight.

3. The impact switch of claim 1 wherein said first electrical contact is a resilient metal member having one portion thereof fastened to said second means and being normally retained in a deformed state by said frangible rod. 1

4. A warning system comprising:

a source of electrical current;

means coup-led to-said source for periodically inter-v rupting said electrical current;

a visual warning device; and

an impact switch coupling said source of electrical current to said visual warning device whereby an impact causes periodic actuation of said device; said impact switch including:

' an inertial element;

a frangible rod having a longitudinal axis and supported at one end thereof by said inertial element;

a first electrical contact supported by the other end of said frangible rod; 1 I

first means intermediatethe ends of said frangible rod for preventing lateral movement of said rod but allowing longitudinal movement of said rod;

a second electrical contact; and

a second means for supporting said second electrical contact intermediate said first electrical contact and said first means whereby breakage-of said rod by movement of said inertial element causes longitudinal movement of said rod so that contact is made between said first and second electrical contacts.

References Cited by the Examiner UNITED STATES PATENTS 2,702,328 2/ 1955 Collins ZOO-61.46 X

FOREIGN PATENTS 788,175 7/1935 France.

BERNARD A. GILHEANY, Primary Examiner.

J. I. BAKER, Assistant Examiner. 

1. AN IMPACT SWITCH COMPRISING: AN INERTIAL ELEMENT; A FRANGIBLE ROD HAVING A LONGITUDINAL AXIS AND SUPPORTED AT ONE END THEREOF BY SAID INERTIAL ELEMENT; A FIRST ELECTRICAL CONTACT SUPPORT BY THE OTHER END OF SAID FRANGIBLE ROD; FIRST MEANS INTERMEDIATE THE ENDS OF SAID FRANGIBLE ROD FOR PREVENTING LATERAL MOVEMENT OF SAID ROD BUT ALLOWING LONGITUDINAL MOVEMENT OF SAID ROD; A SECOND ELECTRICAL CONTACT; AND SECOND MEANS FOR SUPPORTING SAID SECOND ELECTRICAL CONTACT INTERMEDIATE SAID FIRST ELECTRICAL CONTACT AND SAID FIRST MEANS WHEREBY BREAKAGE OF SAID ROD BY MOVEMENT OF SAID INERTIAL ELEMENT CAUSES LONGITUDINAL MOVEMENT OF SAID ROD SO THAT CONTACT IS MADE BETWEEN SAID FIRST AND SECOND ELECTRICAL CONTACTS. 